The present invention generally relates to a conveyor device operative for conveying material away from a mine face, an excavation roof support device operative for supporting the roof of the excavation, and a hydraulic control unit operatively connected to both of these devices and operative for advancing one of the devices towards the mine face while the other of the devices remains stationary, and vice versa. More particularly, the present invention relates to means for guiding the advancing device during its advance towards the mine face.
It has been proposed in the prior art to connect a guiding arrangement intermediate a conveyor device and an excavation roof support device. With the aid of a hydraulic piston-cylinder control unit, the guiding arrangement serves to push one of these devices towards the mine face, and subsequently to pull the other of the devices stepwise towards the mine face. The guiding arrangement is pivotally connected with play to these devices so that slight freedom of relative movement exists during either the pushing or pulling stepwise movements.
The known guiding arrangements generally are comprised of one-piece, welded box-shaped sections which are not detachable from each other. Furthermore, the known guiding arrangements are of rigid massive construction. In other words, they cannot readily flex or yield to any appreciable extent. During normal operation, the guiding arrangements are subjected to relatively heavy loads which tend to frequently destroy the guiding arrangements or bend them to such an extent that they are no longer fit for use. The guiding arrangements which are very costly items must therefore be entirely replaced. Under normal operating conditions, this is very difficult and time-consuming, particularly in cases where mining personnel work in excavations having a height on the order of 0.5 meters.